Biffy Clyro have become the first rock band to play a gig in Parliament.
And House of Commons Speaker John Bercow said the gig at the Palace of Westminster could be the first of many similar concerts as part of his efforts to help Parliament "reconnect" with modern Britain.
The Scottish three-piece played a half-hour acoustic gig organised by Absolute Radio.
Singer Simon Neil described the event, in a marquee on the Commons terrace looking over the Thames, as "very surreal" and the band could barely stifle their giggles as he shouted out "Order!" in imitation of the Speaker to quieten the audience between songs.
He agreed it was "the weirdest place we've ever played" after rounding off the show with top 10 single Mountains.
The gig was arranged to mark the first anniversary of the launch of Absolute Radio, and among the 200-strong audience were some of the station's DJs, including Christian O'Connell and Frank Skinner, alongside a smattering of MPs.
Parliament has witnessed a few musical performances before, including appearances by R&B star Alicia Keys and folk veteran Ralph McTell, and the Commons rock band MP4 - made up of four MPs - has played in the terrace pavilion. But Thursday night's show is believed to be the first full-scale gig by a mainstream rock act.
It was arranged by the chairman of the Commons Culture, Media and Sport Committee, John Whittingdale, who is known in Parliament for his eclectic musical tastes.
The Maldon and Chelmsford East MP declared the set "fantastic", adding: "I'm a big rock fan and I already liked Biffy Clyro."